1. Field of the Invention
The present invention relates to a health care technology for measuring and monitoring a change in a body, and more particularly, relates to accessories placed on a body of a user to measure a change in the body of the user or condition of the user and communicate with an external apparatus.
2. Description of Related Art
A ubiquitous system indicates an information communication environment in which a user is unaware of a network or a computer and whose position is irrelevant while the user freely access the network. When a ubiquitous system is generally used, every one can use information technology in varied embodiments. Thus, a user could, for example, not only use such technology in a house or vehicle but also on the top of a mountain. Also, since the general use of a ubiquitous system increases the number of users of computers connected to a network, the information technology industry may be also expanded to a size and range in relation to the number of the users. Due to merits of not only portability and convenience, as described above, but also accessing a network in which time and position are irrelevant, technologies associated with Ubiquitous system are being developed in nations worldwide.
The described technologies associated with ubiquitous systems may be applied in every field of human life, and currently, in particular, due to the well-being fad, a ubiquitous healthcare (U-healthcare) is in the spotlight as a notable technical field. U-healthcare is a ubiquitous technology in which a chip or sensor associated with medical services is integrated into any part of human life, thereby naturally providing medical services to everyone at anytime and anywhere. According to the U-healthcare, medical treatments performed in only hospitals, such as various medical examinations, management of diseases, emergency care, and consulting with doctors, may be realized during everyday life.
As a result, a device capable of measuring or monitoring a change in a body or a peripheral environment may be required. Also, according to development of a technology associated with integrated circuits (IC), a circuit capable of performing desired functions may be embodied in one chip. Accordingly, according to the level of present technology, the size of a circuit unit may be minimized to several mm or less.
Also, since technology associated with antennas is continuously developed, the size of an antenna may be minimized. Generally, a small device including wireless communication function may employ a monopole antenna because the monopole antenna having a quarter (¼) length of a wavelength of a used frequency may perform efficient communication function. Also, recently, greater minimization of antennas has been made possible by employment of dielectric material or improvement of technology of antenna patterns. For example, when a monopole antenna is used for a frequency of approximately 2.45 GHz, a required length of the antenna is approximately 3 cm, and when a dielectric material or a particular pattern is used, the size of the antenna may be manufactured to be less than approximately 1 cm.
When a device for monitoring a change in a body or environments is placed on a body, a functional circuit and antenna may be minimized to a desired size. However, a ground has to have a length of ¼ wavelength, and when a monopole antenna is used in a frequency band of approximately 2.45 GHz, a required length of a ground has to be at least approximately 3 cm.
Accordingly, to manufacture a monitoring device placed on a body in a small size, since a ground of a certain length is required, there are many restrictions to manufacture the monitoring device in a micro size. Actually, when a ground is formed on a printed circuit board (PCB), as the entire size of the PCB is reduced, an area in which the ground is formed is also reduced and the antenna cannot perform its function.